$ git clone -n https://gitee.com/mgb01105731/libcxx.git /var/lib/mock/dist-an23-build-540501-84787/root/chroot_tmpdir/scmroot/libcxx
Cloning into '/var/lib/mock/dist-an23-build-540501-84787/root/chroot_tmpdir/scmroot/libcxx'...
$ git fetch origin e7803f4bbbe1fcbb5157d69928d7ea54a40ba81a:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/libcxx
 * [new ref]         e7803f4bbbe1fcbb5157d69928d7ea54a40ba81a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e7803f4 Update to 17.0.6